1. Field of the Invention
The present invention relates to a lithium secondary battery and a method of fabricating the same, and more particularly, to a pouch type lithium secondary battery and a method of fabricating the same having a simplified packaging process.
2. Description of Related Art
Typically, in a lithium secondary battery, a lithium based oxide is used as a positive active material, and a carbon based material is used as a negative active material. The lithium secondary battery can be classified into a liquid electrolyte battery and a polymer electrolyte battery depending on a type of the electrolyte. The liquid electrolyte battery is often referred to as a lithium ion battery, and the polymer electrolyte battery is often referred to as a lithium polymer battery. In addition, the lithium ion battery is fabricated in various shapes such as a roll type, a polygonal type, and a pouch type.
Among them, the pouch type lithium secondary battery has a pouch exterior including a metallic foil and a multi-layered synthetic resin film covering the metallic foil layer. The pouch type has been increasingly used and developed as a light-weight lithium secondary battery because it is possible to significantly reduce the weight of the battery in comparison with a polygonal type or a roll type which utilizes a heavier metallic can.
A conventional method of fabricating the pouch type lithium secondary battery will now be described in brief. First, an electrode assembly is arranged on a second side of a pouch exterior having a space for storing an electrode assembly. Then, the second side is covered with a first side of the pouch exterior, and the pouch exterior is sealed, so that a pouch bare cell is obtained. Subsequently, accessories such as a protection circuit module are attached to the pouch bare cell to provide a pouch core pack, and the pouch core pack is inserted into a battery package case, so that a pouch type lithium secondary battery can be finally provided.
However, according to a conventional method of fabricating a pouch type lithium secondary battery, a separate battery package case should be used. Therefore, a fabrication process takes relatively long time. This fact has limited a manufacturing yield of the pouch type lithium secondary battery.
In addition, cost reduction of the pouch type lithium secondary battery has been limited by a separate battery package case.